Field of the Invention
This invention relates to elastic supports for supporting stuffing or upholstery of furniture pieces such as bedsprings, beds chairs and the like and more particularly an improved support member of the type referred to.
Description of the Prior Art
The use of elastic belts for supporting the stuffing or upholster in furniture pieces such as seats, backs, arm rests, backboards, motorvehicle seats and backs and the like is well known. The elastic belts of this kind at present in use are affected by various disadvantages such as for example a lack of uniform spring suspension because each belt applied to the supporting frame has not the same tension as the other belts which are stretched and applied one at a time and therefore the more stretched belt "works" more than the other belts and supports alone all the weight of the user thereby fringing and breaking prematurely and causing also the other belts to fringe and break. These elastic belts have been improved by the Applicant by providing on the elastic threads a spirally wound covering formed of natural or synthetic yarns.
From the Italian Patent No. 955 134 a support of this kind is also known, which comprises an elastic net formed of a net or honeycomb fabric made of rubber threads or the like arranged at least in one of the transverse and longitudinal directions, which rubber threads are covered with a plurality of spirally wound yarns and preferably crossed in the other direction by elastic or not elastic threads of nylon or cotton or other suitable textile fibers.
However, also this support is affected by drawbacks due to the fact that the plurality of spirally wound yarns, while overcoming the drawback of the uniform spring suspension, require expensive working operations and the use of a great amount of textile yarn, which makes the spiral winding very expensive.
In an attempt to overcome this drawback, use is made of a yarn spirally wound in one direction and a yarn spirally wound in the opposite direction, but this has not solved the problems that the spiral winding involves.
Therefore the elastic threads covered by a plurality of spirally wound yarns, in spite of the precautions taken, lead to tension differences of the covered elastic threads at the time of their manufacture, what gives effect of false twisting and ondulations of the elastic support members obtained thereby.